*2.1.7 Antidiabetic treatment and macular edema*

The correlations between antidiabetic mellitus medication and the risk of macular edema is still a subject of research. In a comprehensive systematic review and meta-analyses, Zhu and col. found that insulin use, as well as thiazolinedione (TZD) and meglitinide might increase the risk of macular edema, metformin has no statistically significant effect, while the use of sulfonylureas seems to have a protective role [43]. The physiopathological mechanisms are not completely understood, but experimental studies indicate that insulin and TZD may induce changes in retinal flow and increased expression of VEGF and breakdown of retinal-vascular barrier [43–46].
